Abrasive cutoff machine



March 30, 1 943. s c RE 2,315,090

' ABRASIVE CUT-OFF MACHINE Filed Jan. 29, 1941 I -Q&:

INVENTOR STANLEY C DRE/15R.

A-r-roRuEv:

Patented Mar. 30, 1943 UNITED STATES hTENT OFFICE 2 Claims.

My invention relates to abrasive cut-off machines for cutting structural material either with a 90 cut or at any predetermined angle and wherein the structural material being cut is held on a table and a revolving abrasive wheel is brought down onto the material so as to cut therethrough.

t is an object of my invention to provide an abrasive cut-01f machine of relatively light but sturdy construction taking up the minimum of space and permitting the greatest speed in the actual cutting.

It is a further object of my invention to provide an abrasive cut-off machine wherein the plane of rotation of the abrasive cutting wheel is rigidly maintained at all times to prevent the breaking of the wheel during the cutting; V

A further object of my invention is to provide a cut-oil machine wherein the abrasive cutting wheel is completely housed for safety sake but which housing is readily and quickly removable for the changing of abrasive wheels.

A further object of my invention is the provision in combination with an abrasive cutaofi machine, as above described, of a manually oper-. ated material clamp which may be quickly applied to the material and removed from the material without the necessity of tightening or loosening bolts or worms.

It is also an object of my invention to, provide an abrasive cut-off machine having all of the above advantages as to safety; speed, flexibility and accuracy and which may be manufactured at a relatively low cost.

These and other objects of my invention which will be set forth hereinafter will be apparent to one skilled in the art upon reading this specification, I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplary embodiment. Reference is now made to the drawing which forms a part hereof and in which:

Figure 1-is a side elevation of my novel cutoff machine.

Fig. 2 is a front elevation of my novel cut-off machine with unimportant portions broken away.

Fig. 3 is a plan view of my novel cut-off machine.

Fig. 4 is a cross section taken on the section line t i of Fig. 2 of my novel cut-off machine showing my novel material clamp.

Fig. 5 is a cross section taken on the section line 55 of Fig. 2 showing the abrasive cutting wheel and the dust chute.

Briefly, in the practice of my invention I provide a table i upon which is mounted by means of a platform 2, a motor Bhaving a driving shaft 4. The motor 3 is mounted at or beyond the rear of the table I.

Mounted on the motor 3 so as to pivot around the motor shaft axis 4 is an arbor 5. The arbor 5 projects and hangs over a forward portion of the table I and mounted in the arbor 5 at the hanging over portion is a shaft 8 parallel to the shaft 4 of the motor 3. The motor shaft 4 carries sheaves in line with sheaves upon the driven shaft 6. The sheaves on the motor shaft are belted to the sheaves on the driven shaft 6 so that revolutions of the motor shaft will revolve the driven shaft 6 as is apparent in Fig. 3.

Mounted on the driven shaft 6 is an abrasive cutting wheel 1. There is a. clearance slot 8 cut in the table I below the abrasive cutting wheel I so as to permit entry of the cutting wheel i when it is in its lowermost position.

An arm 9 projects downwardly from the arbor 5 from a point axially in line with the motor shaft 4. This arm 9 is urged toward the table I by means of a spring l0 and the, distance is determined by an adjustable stop thereon and, an abutment H attached to the motor platform 2 as is apparent in Fig. 1. There is a link l2, one end of which is pivoted to an intermediate portion of the arbor 5 and after running through the table I, is attached at its other end to an arm I3 actuated by a pedal 1 t.

From the above, it is apparent that thearbor 5 carrying the cutting wheel 1 may be rocked or pivoted around the motor shaft 41in such a mannet as to. lower the cutting wheel I by actuation of the foot pedal 2 4; and that upon release of the pedal it the spring Iii, through the lever arm 9, pivots the arbor 5 around the motor shaft 4 thus lifting the cutting wheel 1 until the arm 9 contacts the abutment H.

Running along the front of the table l is rod I5 fastened at each end to the table I by means of cleats l6. Pivoted to this rod l5 by one of its ends is a housing H in the form or a hood. The housing I! is so formed as to cover the abrasive cutting wheel I with its other end it resting upon the table I. While the housing l'i effectively hoods the wheel I on its peripheral surface as well as its exposed side, there is a portion I!) cut out to permit the entry of structural material to be out under the hood. There is also a cut out slot or portion 20 in the side of the hood I! which permits the shaft 6 to project through the hood and into the arbor 5. The hood I! and the aperture 28 are so configured as to permit full vertical reciprocation of the cutting wheel I together with its driving mechanism throughout its operating stroke.

,.'-Io one side of the path of the cutting wheel I and mounted on'the table I is a material clamp for holding the material while it is being cut. This clamp comprises a backing plate 22 which is pivoted to the table I by means of a pivot 23 close to the cutting plane of the wheel 1. The backing plate 22 may.be the vertical fin of an L shaped section, the horizontal fin of which forms a journal through which the pivot pintle at 23 may go. I do not intend to limit myself to the manner of pivoting the backing plate 22 since there are many ways it could be pivoted to the table I. Cut in the table I is a curved slot 24 under a portion of'the backing plate 22 and on the circumference of a circle the center of which is the pivot point 23. A thumb screw or any other known type of frictional arrangement 25 is attached to'the backing plate and enters the slot 24. In the drawing I have shown a wing nut arrangement which permits the pivoting of the backing plate 22 on the pivot point 23 so that the plane of the backing plate'22 will present different angles to the cutting plane of the wheel 1. I I

The remaining portion of the clamp comprises a bifurcated lever arm 21 having a handle 28 at one end and one of the forks at the other end being pivoted on a sliding pivot 29 parallel to the backing plate 22 and behind the same. The other fork 38 of the arm 21 is so configured as to contact the face of the backing plate 22 when the handle portion 28 is lowered and so as to leave the backing plate 22 when the handle portion 28 is raised as illustrated in Fig. 4. An abutmentc3l is preferably formed in the pivoted fork of the lever'2I so as to limit the upward movement of the lever 2! by means of its handle 28.

The action of the clamp is well illustrated in Fig. 4. As is apparent, the clamp is open when the handle 28 is in its upward position as shown by the broken lines. Material to be worked upon which is in the form of long channels or rods, etc., is placed against the backing plate 22 and when the lever 21, by means of its handle 28, is

brought downwardly the end of the fork 38 abuts against the material-and clamps it between the fork 38 and the backing plate 22 irregardless of the width of thematerial being worked on. It is also apparent from Fig. 3 that the angle of the material being worked on may be varied as to the cutting plane of the wheel I by varying the angle of the backing plate 22 to the plane of the wheel I as heretofore described. The clamp is held in clamping position by the downward pressure of the operator upon the handle 28 and as soon as this pressure is released, the material may be easily removed from the clamp.

In conjunction with my clamp I have provided members 35 which are so positioned when in place that the material being worked on rests upon them. These members 35 are so positioned in reference to the cutting plane of the wheel I that the portion of the material being clamped is held above the surface of the table'I and so that the portion of the material projecting beyond the plane of the cutting wheel I has no support. The purpose of this construction is to form a platform permitting the outer hanging portion of the material to pull downwardly by reason of gravity and thus prevent any binding of the cutting wheel I as it travels through the material being cut. I preferably make the members 35 removable as by the pivoted connections to rod I5, so that if light pieces or pieces having shapes which do not tend to bind the cutting wheel are used, the material may be laid directly upon the table I on both sides of the cutting wheel 1.

As is apparent in the drawing, I have provided an adjustable abutment or gauge 31 which may be adjusted along the rod I5 and completely thrown out of operation if desired. I also provide a dust chute 38 to carry off the metal dust inherent in the cutting operation.

The normal operation of my novel abrasive cut-off machine is as follows. The operator first adjusts the clamp by means of the wing nut arrangement25 in the slot 24 of the table I to a predetermined angle with the plane of the cutting wheel I so as to predetermine the angle of out. If necessary the gauge 31 is placed in a predetermined position. The material to be cut is then preferably placed upon the members 35 and projected under the cutting wheel I to its predetermined position. The operator by means of his left hand then brings down the lever 21 by pressing on the handle 28 so that the material is clamped between the clamping plate 22 and the end of the fork 38. While holding the lever 21 down by means of his left hand, the operator then pushes down the pedal I4 with his foot. This rocks the whole arbor 5 on an axis coextensive with the motor axis and brings the revolving cutting wheel I down onto the work. The opera tor keeps pressing on the pedal I4 as the cutting wheel cuts through the material. By reason of the pull of gravity on the portion of work pro jecting to the right of the cutting wheel, the cutting wheel I does not tend to bind in the work since the cut tends to pull open. After the cut is made the operator releases the pedal I4 which permits the cutting wheel I to rise by reason of the rocking of the arbor 5 because of the pull of the spring I8. After the cutting wheel I has been removed from the work the lever 27 is raised and the finished work may be removed from the machine. During all of these operations the guard hood I! houses the revolving cutting wheel I. In the event that the cutting wheel must be changed, the guard I! is merely pivoted on the rail I5 which exposes the cutting wheel and permits its easy removal and replacement.

It is understood that different forms of my preferred form may be made without departing from the spirit of my invention. Having now fully described my invention what I claim as new and desire to secure by Letters Patent, is:

1. In an abrasive cut-off machine, the combination of an arbor associated with a motor and carrying an abrasive wheel rotated thereby, said arbor being mounted on and pivoted for movement of the abrasive wheel in a vertical plane around an axis coextensive with said motor axis and a guard substantially inclosing the abrasive wheel and pivoted at one end thereof to a work table for removing the guard and a clamp comprising a backing plate and a bifurcated lever pivoted thereto by one of the forks so that movement of the lever will vary the distance between the other fork and the backing plate mounted on the work table.

2. In an abrasive cut-ofi machine, the combination of an arbor associated with a motor and carrying an abrasive wheel rotated thereby, said arbor being mounted on and pivoted for movement of the abrasive wheel in a vertical plane around an axis coextensive with said r'notor axis and a guard substantially inclosing the abrasive wheel and pivoted at one end thereof to a work table for removing the guard and a clamp com- 

